Grab



June 21, 1927.

D. J. BARNARD GRAB Filed March 7I 1,924A 6 Sheets-Sheet 1 2 n B umu w f m O A. .wf Q4 O h im O O 3 .lIlTllllllll MW 3 Julie 21, 1927.

D. v.1. BARNARD GRAB Filed March 7. 1924 6 Sheets-Sheet 2 IEN- limi...

June 21 1927.

D. J. BARNARD GRAB Filed Ma'rqh v, 1924 6 Sheets-Sheet 5 /L 'I'. Il

men/70A' June v21, 1.927.

D. J. BARNARD GRAB e sheets-sheet 6 Filed March '7, 1924 Patented June 21, 1927.

`UNITED- STATES PATENT OFFICE. i

DUDLEY JAMES BARNARD, OF BAB/KING, ENGLAND.

GRAB.

Application filed lMarch 7, 1924, Serial No. 697,657, and in Great Britain March 14, 1923.y

tents, closed, and opened and closed again as f often as desired until the bucket is empty, without dumping the grab.

It is proposed to attain the objects of this invention by the provision of means on the head of the grab adapted to be automatically actuated by certain moving parts of the grab and 'to coact with a tipping ring'suspended from the jibof the crane. v

In the accompanying drawingsfwhich illustrate this invention Fig'ure 1 is a side elevation of a grab partly in section with the buckets in the closed position, the load being supported by the hauling chain.

Figure 2 is a front elevation thereof.

s Figure 8 is a front elevation partly in sectign showing the bucketsy in al partly opened position, the load 'being supported by the tipping ring.

Figure 4 is a similar view partlyin section showing the buckets in the fully opened position. f

Figure 5 is a side elevation, on an enlarged scale, of the head of the grab illustrating that part of the mechanism adapted to co.

operate with the tipping ring.

Figure 6 is a section online 6-6 of Flgure 5.-

Figure 7 is a similar view showing the parts in another position. U

Figures 8, 9, and 10 are similar views to Figures 5, 6 and 7 respectively of a modification, and

Figures 11, 12 and .13 are similarviews to Figs. 5, 6 and 7 respectivelyy cfa further v modiiication.

' been removed in Figures 1, 3 and 4.

In the drawings, 1 and 2 are the bucket sections pivoted` on independent pins 3 and 4 on a cross-beam 5, 6 and 7 are the top cross bars and 8 the spreader arms, one being arranged at each corner of the bucket sections. The means for maintaining the normal balance of the operative parts of the grab conbles 11 and 12 carried by the lowerl sheave.

block plates 13 and 14.

The mechanism adapted to co-operate withv the tipping ring is illust-rated on an enlarged scale in Figures 5, 6 and 7 modilications thereof inFigures 8 to 13. e

Accordingto the construction illustrated in Figures 5 to`7the sheave block plates 15,

' 16 carried by the top cross bars 6, 7 are provided on each side with a pair of brackets 17 to the upper part of each of which is pivoted a hook shaped element 18 the upper ends of which are adapted to co-act and engage with a tipping ringy 19 (Figures 1, 3 and 4) suspended from the jib of the crane. The lower end of each of the elements 18 is furnished with a projection 2O adapted to enter re-` cesses 21 provided inthe weightelements 22 slidably arranged betweenthe brackets 17. The elements 22 are maintained in position by pins `23 secured in the brackets 17, said pins passing through slots 24 providedin the elements 22 the length of such slots determining the rise and fall of the elements 22.

Thelower ends of the elements 22 are adapted to coact with buffers 25 provided on the lower sheave block plates 13, 14.

When the grab is lsupported by the hauling chain 26, and the gravity catches 27 are in the locking position as shown in Figure l, there is a space between the upper face of the lower sheave block and the lower face of the uppersheave block so that the ele'- ments 22 are free to fall into their lowest position and the weight thereof is such that they maintain the upper ends of the hook shaped members in their innermost position (Figures 2 and 6). When it is desired to discharge thecontents oi the grab, the hauling chain is drawn in so as to raise the grabup to the ti ping ring 19. The weight of the ring issuc that it will force the hook shaped elements 18 outwardly against the pull of the Weight elements 22 until the f 27 is maintained l'in its locked position,l that is, in engagement with the pin 28 carried by thec'ross b'ealn "5.' When it is vdesired to y completely open Jthe lbucket sections the haulv"ing chain is paid `out toV anextent which V'will vcause the outwardly lextending Varm of the catch 27 to engage with 'the part 29 provided 'onthe lower end of an arm 30 pivoted 'at"`8'1 to the block plate 15, which thereby "causes thedisengagement ofthe catch 27 and the 'bucket sections tall inte' the sesrtum shown .iin "Figure fl. The 'upper end ol the 'arm 30 is so shaped that it coasts with a lp'afrt '32 finouilted on the top crc-ss bar 6 "which 'limitsfthe swinging movement oi: said arm.

sVV-hen it is desired l'o Ltree the grab Yl'rem the t1 eine' rm the haullurv cnam is drawn v'in'and theflower lsheave bleek `raised to its highest .position so as `to bring 'the 1outliers Q5 into engagement with and `raise trie weight 'elements 90 a lslight further upward move- 'ment ofthe/'grab releases the hooks from the fand they lfall outwardly as shown in' Figur-e v7. The grab may new be lowered freffro'm the -`ring on to the material to` be A'raised and closed in the lusual manner.

In jtliemodilied form et' mechanism illus- :"trate'd vin Figures 8, 9 and 10, the'hook shapedielements 18 are pivoted inthe brack- :etss17 en "pins 83, thelelements 18 being sov Vshaped and yprovided with weights 34, 85, that 'their upper hoek shaped ends :always t'all Ainwards towards the centre as shou'n in :Figure j9 except when the bucket sections' vare fullyopened and the lower she-Jive jblock yas shown :in Figure 1-0. 'construction the buffers 25 on 'the lower 'p'latesll p and 14 aire'iu thoirihighestposition,

liu this 'form et sheave block vlates are, )rererablv arraned to extend outwardly and upwardly as shown x 1 i `se ythat as the lower block '1s' raised 'towards the 'upper block, Ythe 2lower ends e1" the -eleinentsj18 'and of the weights are .gradually forced inwardlyI until the upper lhook Y Ishaped'ends aire ercedeutx'vartllyou't'fet eny 'gagement with the ring 19. i

In the modified form 'of' construction illustr'ated in 'Figures 111, '12 and "13, the hook shaped elements '18 are shaped similarly te 'those 'shown in `Figures 5, 6 and 7 "but 1the projectiensfQO on the lower ends 'thereof are caused to engagewitli recesses 36 lprovided in the upper ends ler" rods f3? lsli'dably arranged in lugs 0r guide-S38, '39 provided Vgo'n the 'bleek plates 15 and `16 Yand located between "the brackets 17 supporting 'the ve'rlements 18. The "lower end ei yeach of the is, 112i.

Vpath of the tippingfrinb l'reds 37 is .provided with 'a collar ll() 'between which and the 'guide 38 is located va spring` l1 which serve to `maintain thev rods 37 in their Alovrwermost 'position and 4said rods are arranged to extend below the bottom et the .upper block plates 15, 16 and tov coact with buffers 25 provided on the lower block plates l/Vhat I claim is z-vo y .-1. ln a* grab of the vsingle cham'type hav- .ing [a cross-beam, movable sheavefbloek,

vmeans Tor connecting 'the cross-beam and slieave y'block Aand a tipping irme, :theyconibination oit 'devices located at the head et `the grab adapted to 'co-act with said vtipping ring, 4means carried 'by the said movable sheaveb'lock adapted to m'ov'esaid devices out ooi engagement with and out or" tlie ypath of said tipping ring and means zpivoted to the headof the grab 'adaptedlto vce-act with l'the imeans lconnecting the eress-beamand sheave block'to effect the complete `opening of the grab.

2. In a grab ofthesingle chain type hav-V ing va cross ibeann a movable `s'heave bleek, means connecting fthe cross beam and istie ave block, brackets, a tippmg'ring, the combination of a vpair of hook-shaped yelements pivoted in said brackets -andi'lying ithe ab, -buflers on saidy movable sheave fblo'e'k, means connected to said hook-shaped 'elements adapted te eoact with said buffers tor 'moving said elements outofengagement with and .out of the lpath of 'said tipping ring, A:and a ydepending arm carried by the grab adapted toengage with land Leect the disengagement est 4the means :connecting the cross Vbeam and movable sheave block. n

3. `In a 4grab oit the single having` a sheave block aud plates therefor7 a ti.1.)piug-ring, 'a lower sheave `Vblock and 'plates therefor, and aeross beam, the "oombination of two pairs el brackets secured one on each sideof they upper lsliea've block plates7 al pa'irotl eppositely disposed hookshaz'ped elements pivetally fmoi'uited in'said brackets and [adapted to engage with said tipping "ring, means ylocated ybetween the brackets on the upper block plates, lmeans "carried by the lfowersheave 'block plates adapted to coact with said lastiained means tecon'trdl Vthe 'movements of the hook-'shaped -elements `according 'te the relative "position of the lower block plates with respectlte'the upper block plates, a gravity catch pivotally mounted y0n the lower block plates, means provided on said cross beam w'th'whiehsaid gravity catch engages, and "means V'pivotally fmeun'ted Aon lthe lupper block plates adapted to vceact with saidigravity catch to withdraw same from engagement with the means on said cross beam. f

y lil.. n a grab of lthe single 'chain type "having'acress'beam, a movable sheave block,

loo

lZO

means connecting said cross beamk and movable sheave block, upper sheave block plates, a tipping ring, a lower sheave block and plates therefor, the combination of two pairs of brackets secured one on each side of the upper sheave block plates, a pairvof oppositely disposed hook-shaped elements pivotally mounted in said brackets and adapted to engage with said tipping ring, means located between the brackets on the upper block plates connected with said hook-shaped elements, means carried by the lower sheave block plates and cooperating with said last named means to control the movements of the hook-shaped elements according to the relative position of the lower block plates with respect to the upper block plates, and means carried by the grab adapted to effect the disengagement of the means connecting the cross beam and movable sheave block.

5. In a grab of the single chain type having a cross beam, a movable sheave block,

means connecting said cross beam and block, upper sheave block plates, a tipping ring, a lower sheave block and plates therefor, the combination of brackets secured at the sides of the upper sheave block plates, hookshaped elements pivoted to said brackets for engagement with said tipping ring, means connected to said elements and located between the brackets on the upper block plates, and means carried by the lower sheave block plates for coacting with said last named means to control the movements of the hookshaped elements according to the relative position of the lower block plate with respect to the upper block plates.

6. In a grab of the single chain type, the combination of an upper sheave block, brackets secured thereto, hook-shaped elements pivoted in said brackets, a tipping ring for engagement 'by said elements, a lower sheave block, cooperating means on the upper and lower sheave blocks for controlling the movements of the `hook-shaped elements according to the relative position of the lower block with respect to the upper block, a gravitycatch pivoted on the lower block, a cross beam providedwith a pin for engagement by said catch, a depending arm having a limited swinging movement pivotally mounted on the upper block, said gravity caftchhaving an extending arm to cause disengagement of the catch from the pin on the cross beam.

7. In a grab of the single chain type, the.

combination of a pair of hook-shaped elements, brackets on the grab in which said elements are pivoted, a tipping ring for engagement by said elements, a movable sheave block7 buffers on the movable sheave block adapted to move said elements out of engagement with and out of the path of said tipping ring, a gravity catchcarried by the sheave block, bucket sections, a cross beam to which said bucket sections are pivoted, said cross beam having a pin for engagement by the gravity catch, and a depending arm having' a limited swinging movement pivoted on the upper sheave block adapted to engagewith and move said gravity catch out of engagement with the pin.

8. In a grab of the single chain type having a cross-beam, a movable sheave block, means for connecting the cross-'beam and sheave block, brackets in the head of the block.

DUDLEY JAMES BARNARD. 

